WW2 over 70 years ago was a continuation of WW1 fought over 100 years ago.
WW1 was fought by two colonial powers largely over their competing threats to their colonial holdings. The US belatedly, and strategically, joined both wars as an opportunist seeking to enlarge it's worldwide political and economic footprint at a time when the other major parties were debilitated by those wars. Nothing at all about" just wars"
Japan joined in because the US had been aggressively denieing it of access to the required resources for it's economic progression.
The geopolitical landscape present in the first half of the last century is of little relevance now except in the minds of too many nostalgic buffs and members of their powerful armaments industries in the US and Britain " Make America/Britain Great Again" camp.
The armaments industry needs international conflict for it's very existence so stirring those nationalistic pots is an extraordinarily important part of their existance, and therefore imbedded in the economic and political cultures of those players.
I think China would far rather just continue to buy up those Australian coal and iron ore mines rather then invade and get caught up in a hostile occupation scenario. Invade NZ? as a stepping stone to Antarctica? Perhaps if global warming makes Antartica habitable and swathes of China uninhabitable.
What 2 colonial powers were those? Germany had very few colonies and the UK and France were on the same side. Japan had turned expansionistic and militarist well before we cut access to raw materials. In fact, that's sorta why we did it. The Chinese don't have to invade NZ, they'll just send their fleets of factory fishing trawlers down there and denude your EEZ and there's not a thing that you can do about it. Your isolationist attitude is losing you allies.